Trocar assembly with rotatable obturator housing

ABSTRACT

A trocar system includes a cannula having a cannula housing and a cannula sleeve extending from the cannula housing, and an obturator at least partially positionable within the cannula. The obturator includes an obturator housing adapted for mating with the cannula housing, an obturator shaft connected to the obturator housing and receivable within the cannula sleeve, an obturator blade connected to the obturator shaft, a protective member including a protective guard coaxially mounted about the obturator blade and a latch member associated with the obturator housing and operatively connected to the protective guard. The obturator shaft and the obturator blade are adapted for relative rotational movement. The protective guard is adapted for longitudinal movement between a first position substantially enclosing the obturator blade and a second position to at least partially expose the obturator blade. The latch member is moveable from an initial position securing the protective guard in the first position to an actuated position operatively releasing the protective guard to permit the protective guard to move to the second position thereof. The latch member is preferably adapted to move to the actuated position upon mating of the obturator housing and the cannula housing.

BACKGROUND

1. Technical Field

The present disclosure relates to a trocar assembly for use in minimallyinvasive surgical procedures, such as endoscopic or laparoscopic typeprocedures.

2. Background of the Related Art

Minimally invasive procedures are continually increasing in number andvariation. Forming a relatively small diameter temporary pathway to thesurgical site is a key feature of most minimally invasive surgicalprocedures. The most common method of providing such a pathway is byinserting a trocar assembly through the skin. In many procedures, thetrocar assembly is inserted into an insufflated body cavity of apatient. In such procedures, the trocar assemblies with seal mechanismsare utilized to provide the necessary pathway to the surgical site whileminimizing leakage of insufflation gases.

Trocar assemblies typically include an obturator which is removablyinserted through a cannula. The obturator may include a safety shieldwhich protects against unintentional puncturing by the sharpened tip ofthe obturator. The safety shield includes a mechanism which controls therelative movement and locking of the safety shield. One example of asafety shield mechanism is disclosed in commonly assigned U.S. Pat. No.6,319,266 to Stellon et al., the entire contents of which are herebyincorporated by reference.

Insertion of the trocar assembly through the body wall of the patientcan require the application of significant axial force. Typically,during the procedure, the obturator housing is grasped and pressure isapplied to the assembly. In addition to application of pressure, thesurgeon may rotate the obturator housing, either intentionally orunintentionally, to pass the penetrating tip through the tissue.However, any torquing of the obturator housing may be undesirable,particularly, with an obturator having a flat bladed tip. As rotation ofthe flat bladed tip may cause undesired tearing of tissue.

Accordingly, there is a need for further improvement in trocar obturatorassemblies including assemblies which reduce undesirable tearing oftissue.

SUMMARY

Accordingly, the present disclosure is directed to further improvementsin trocar technology. In one preferred embodiment, the trocar systemincludes a cannula having a cannula housing and a cannula sleeveextending from the cannula housing, and an obturator at least partiallypositionable within the cannula. The obturator includes an obturatorhousing, an obturator shaft connected to the obturator housing, agenerally flat obturator blade connected to the obturator shaft, aprotective member coaxially mounted about the obturator blade and beingadapted for longitudinal movement between a first position substantiallyenclosing the obturator blade and a second position to at leastpartially expose the obturator blade, and a latch member positioned inthe obturator housing to prevent longitudinal movement of the protectivemember. The obturator shaft and the obturator blade are adapted forrelative rotational movement. The latch member is moveable from aninitial position securing the protective guard in the first position toan actuated position operatively releasing the protective guard topermit the protective guard to move to the second position thereof. Thelatch member is preferably adapted to move to the actuated position uponapproximating the obturator housing and the cannula housing.

In one preferred embodiment, the obturator includes a blade mountconnected to the obturator shaft with the blade mount and the obturatorshaft being adapted for relative rotational movement about thelongitudinal axis. The blade mount houses the obturator blade. Theobturator shaft may be secured to the obturator housing wherebyrotational movement of the obturator housing causes correspondingrotational movement of the obturator shaft.

An indicator member may be mounted adjacent the obturator housing andoperatively connected to the protective member. The indicator member ismovable upon movement of the protective guard to the second position toprovide visual confirmation to the user of the positioning of theprotective guard. The protective guard is normally biased toward thefirst position.

The obturator preferably includes a release member mounted to theobturator housing and operatively coupled with the latch member. Therelease member is adapted to move the latch member to the actuatedposition upon mating of the obturator housing and the cannula housing.The release member includes a release button positioned to engage thecannula housing upon mating of the obturator housing and the cannulahousing to thereby displace the release member and cause movement of thelatch member to the actuated position.

The obturator preferably includes an indicator collar disposed withinthe obturator housing and mounted to the protective member. Theindicator collar is adapted for longitudinal movement with theprotective member upon movement of the latch member to the actuatedposition. The indicator collar and the protective member are adapted forrelative rotational movement. The indicator collar may include anindicator member adapted for providing visual confirmation to the userof the positioning of the protective guard.

The cannula assembly may include a seal assembly having a seal housingand an internal seal. The seal housing is mountable to the cannulahousing.

In another preferred embodiment, an obturator assembly for penetratingtissue is provided. The obturator assembly includes an obturatorhousing, an obturator shaft connected to the obturator housing, agenerally flat obturator blade connected to the obturator shaft with theobturator shaft and the obturator blade being adapted for relativerotational movement, a protective member mounted about the obturatorblade and being adapted for longitudinal movement between a firstposition substantially enclosing the obturator blade and a secondposition to at least partially expose the obturator blade, and a latchmember positioned in the obturator housing to prevent movement of theprotective member. The latch member is moveable from an initial positionsecuring the protective member in the first position to an actuatedposition operatively releasing the protective member to permit theprotective member to move to the second position thereof. A releasemember may be mounted to the obturator housing and operatively coupledwith the latch member. The release member has a release buttonpositioned to engage the cannula assembly upon mating of the obturatorhousing and the cannula assembly to thereby displace the release memberand cause movement of the latch member to the actuated position.

An indicator collar may be disposed within the obturator housing andmounted to the protective member. The indicator collar is adapted forlongitudinal movement with the protective member upon movement of thelatch member to the actuated position. The indicator collar and theprotective member are adapted for relative rotational movement. Theindicator collar includes an indicator member adapted for providingvisual confirmation to the user of the positioning of the protectiveguard.

In another preferred embodiment, an obturator assembly includes anobturator housing, an obturator shaft connected to the obturatorhousing, a generally flat obturator blade connected to the obturatorshaft with the obturator shaft and obturator blade being adapted forrelative rotational movement, and a protective member mounted around theobturator blade. The protective member is adapted for longitudinalmovement between a first position substantially enclosing the obturatorblade and a second position to at least partially expose the obturatorblade. The protective member may be rotatably attached to the obturatorhousing.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present disclosure are describedhereinbelow with references to the drawings, wherein:

FIG. 1 is a perspective view of an embodiment of a trocar assemblyconstructed in accordance with the present disclosure;

FIG. 2 is a perspective view with parts separated of the trocar assemblyillustrating the cannula assembly and the obturator assembly inaccordance with the embodiment of FIG. 1;

FIG. 3 is a perspective view with parts separated of the obturatorassembly in accordance with the embodiment of FIGS. 1-2;

FIG. 4 is a side cross-sectional view of the obturator assembly inaccordance with the embodiment of FIGS. 1-3;

FIG. 5 is an enlarged cross-sectional view of the indicated area ofdetail of FIG. 4 in accordance with the embodiment of FIGS. 1-4;

FIG. 6 is a second enlarged cross-sectional view of the obturatorhousing of the obturator assembly in accordance with the embodiment ofFIGS. 1-5;

FIG. 7 is a perspective view of the indicator collar of the obturatorhousing mounted to the shield member in accordance with the embodimentof FIGS. 1-6;

FIG. 8 is a side cross-sectional view of the indicator collar and shieldmember in accordance with the embodiment of FIGS. 1-7;

FIG. 9 is a perspective view of the housing base of the obturatorhousing in accordance with the embodiment of FIGS. 1-8;

FIG. 10 is a perspective view of the housing cover of the obturatorhousing in accordance with the embodiment of FIGS. 1-9;

FIGS. 11-12 are perspective views illustrating the components of thelatch mechanism in accordance with the embodiment of FIGS. 1-10;

FIG. 13 is a perspective view of the obturator shaft and the obturatorblade in accordance with the embodiment of FIGS. 1-12;

FIG. 14 is a side cross-sectional view of the trocar assemblyillustrating the obturator assembly mounted relative to the cannulaassembly and the latch member in an actuated position in accordance withthe embodiment of FIGS. 1-13;

FIG. 15 is an enlarged side cross-sectional view illustrating therelationship of the components of the latch member in an actuatedposition in accordance with the embodiment of FIGS. 1-14;

FIG. 16 is a view similar to the view of FIG. 14 illustrating theprotective shield of the obturator assembly in a retracted position inaccordance with the embodiment of FIGS. 1-15;

FIG. 17 is a view similar to the view of FIG. 15 illustrating therelationship of the components of the latch member when the protectiveshield is in the retracted position in accordance with the embodiment ofFIGS. 1-16;

FIG. 18 is a perspective view illustrating insertion of the trocarassembly within tissue;

FIG. 19 is a view similar to the view of FIG. 18 illustrating rotationof the obturator housing of the obturator assembly;

FIG. 20 is a perspective view of an alternative embodiment of anindicator collar for use with the obturator assembly;

FIG. 21 is a perspective view of a shield member for use with theindicator collar in accordance with the embodiment of FIG. 20;

FIG. 22 is a perspective view illustrating mounting of the indicatorcollar to the shield member in accordance with the embodiment of FIGS.20-21; and

FIG. 23 is a side cross-sectional view of the assembled indicator collarand shield member in accordance with the embodiment of FIGS. 20-22.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawing figures, in which, likereferences numerals identify similar or identical elements, there isillustrated, in FIGS. 1 and 2, a trocar assembly constructed inaccordance with a preferred embodiment of the present disclosure anddesignated generally by reference numeral 10. Trocar assembly 10 isparticularly adapted for use in minimally invasive surgical proceduressuch as endoscopic or laparoscopic procedures. Generally, trocarassembly 10 includes two principal subassemblies, namely, obturatorassembly 100 and cannula assembly 1000.

Cannula assembly 1000 may be any cannula assembly suitable for use in alaparoscopic surgical procedure. In one preferred embodiment, cannulaassembly 1000 includes cannula housing 1002 and cannula sleeve 1004extending from the cannula housing 1002. Either or both cannula housing1002 and cannula sleeve 1004 may be transparent in part or in whole andare fabricated from biocompatible metal or polymeric material. Cannulaassembly 1000 may include an internal seal such as a duck-bill valve orother zero closure valve adapted to close in the absence of a surgicalinstrument to prevent passage of insufflation gases through the cannulaassembly 1000.

Trocar assembly 10 may also include a seal assembly 2000 which ispreferably releasably mounted to cannula housing 1002. Means forreleasably connected seal assembly 2000 to cannula housing 1002 mayinclude a bayonet coupling, threaded connection, latch, friction fit,tongue and groove arrangements, snap-fit, etc. Seal assembly 2000includes seal housing 2002 and at least one internal seal which isadapted to form a fluid tight seal about an instrument inserted throughthe seal assembly 2000. One suitable seal may be the fabric sealdisclosed in commonly assigned U.S. patent application Ser. No.10/165,133, filed Jun. 6, 2002, the entire contents of which areincorporated herein by reference. The seal disclosed in the '133application may be a flat septum seal having a first layer of resilientmaterial and a second fabric layer juxtaposed relative to the firstlayer. Further details of the seal may be ascertained by reference tothe '133 application. Seal assembly 2000 may or may not be a componentof cannula assembly 1000. For example, the seal assembly may be aseparate, removable assembly. In the alternative, the seal assembly maycomprise an integral part of the cannula assembly 1000 and not beremovable.

With reference now to FIGS. 3-4, in conjunction with FIG. 2, obturatorassembly 100 includes obturator housing 102 and obturator shaft 104extending distally from the housing 102. Obturator shaft 104 definesobturator axis “x” and will be discussed in greater detail hereinbelow.Obturator housing 102 includes housing base 106 and housing cover 108.Once the appropriate components are positioned therewithin (as describedbelow), housing base 106 may be attached to housing cover 108 byengaging mating surfaces, for example, by resilient latches 110 of cover108 interlocking with correspondingly dimensioned latch openings 112 ofhousing base 106. Preferably, to uniformly connect base 106 and cover108 at least three corresponding latches 110 and openings 112 are spacedevenly around the circumference of the cover 108 and the base 108,respectively. Preferably, obturator housing 102 is configured anddimensioned to functionally cooperate with cannula that range in size,e.g., from about 5 mm to about 15 mm in diameter.

Obturator assembly 100 includes protective shield 114. Protective shield114 includes shield member 116, shield extension 118 and blade guard 120operatively connected to each other to define an outer member ofobturator assembly 100. In one preferred embodiment, shield member 116is connected to shield extension 118 through an arrangement includingdiametrical tabs 122 extending from the shield extension 118, which arereceived within the internal lumen of shield member 116 in frictionalrelation therewith, or a snap-fit. Diametrical tabs 122 may furtherinclude circular or cylindrical bases 124 which are received withincorresponding openings 126 of shield member 116 in snap relationtherewith. Similarly, blade guard 120 includes a plurality, e.g., four,of axially depending tabs 128 which are received within correspondinglydimensioned tab openings 130 of shield extension 118 to connect the twocomponents. Other means for connecting the components of protectiveshield 114 are also envisioned including snap fit arrangements,adhesives, welding tongue and groove arrangements, etc. In otherembodiments, protective shield 114 is single component. In the assembledcondition, shield member 116 of protective shield 114 extends withinhousing base 106, particularly, cylindrical portion 106 a of the housingbase 106. Protective shield 114 is adapted for axial movement along axis“x” and relative to obturator housing 102 as will be discussed ingreater detail hereinbelow.

Referring now to FIGS. 3-8, obturator assembly 100 further includesindicator collar 132 which is secured within the proximal end of shieldmember 116. In one preferred arrangement, indicator collar 132 definesdistal collar extension 134. Collar extension 134 includes annular rim136 on its outer surface. Annular rim 136 is contained within shieldmember 116 through its engagement with radial tabs 138 of shield member116 as best shown in FIGS. 7 and 8. With this arrangement, indicatorcollar 132 is adapted to rotate relative to shield member 116—which willbe discussed in greater detail hereinbelow.

Indicator collar 132 further includes a shield position indicator, suchas indicator flag 140, extending transversely relative to the indicatorcollar 132. Indicator flag 140 is visible from the exterior of obturatorhousing 102 as it extends through groove 108 a of housing cover 108 (seealso FIGS. 2 and 7). Preferably, indicator flag 140 is colored tocontrast sharply with the surrounding housing components. For example,indicator flag 140 may be red if the surrounding housing components arewhite or light colored. Indicator collar 132 further includes collarledge 144 and a pair of posts 146 formed below the ledge 144 andextending radially outwardly from the ledge 144. Collar ledge 144 servesto releasably lock protective shield 114 in a distal position withrespect to blade 190.

Indicator flag 140 and protective shield 114 are spring biased in thedistal direction by coil spring 148. In particular, coil spring 148 isreceived within internal bore 150 of indicator collar 132 and engagesinternal shelf 152 (see FIG. 8) of the indicator collar 132. Theproximal end of coil spring 138 is coaxially mounted about spring mount154 (see FIG. 10) depending from the interior surface of housing cover108.

Referring now to FIGS. 9-12, in conjunction with FIGS. 3-5, obturatorassembly 100 includes a latching mechanism disposed within obturatorhousing 102 to prevent proximal movement of protective shield 114 untilsuch time as the obturator assembly 100 is mounted to cannula assembly1000 and the surgeon is prepared to begin trocar entry. Latchingmechanism includes latch member 156, and release member such as slider158, as best seen n FIG. 3. Latch member 156 has two vertical legs 160connected by web 162. A pair of biasing posts 164 extends outwardly, onefor each side of latch member 156. Collar ledge 144 of indicator collar132 is engaged and secured by web 162 of latch member 156 when in aninitial position of the latch member 156 as depicted in FIGS. 11-12. Inthe initial position of latch member 156, protective shield 114 isretained in a first extended position shown in FIG. 4. Latch member 156is preferably molded as part of housing base 106 in cantilever fashion.However, latch member 156 may be formed as a separate element andsecured to base 106 by suitable known techniques.

Slider 158 includes post 166 disposed at its lower end, arming button168 extending distally from the distal face of slider 158 and a pair ofslider legs 170 which terminate in crooks 172. Crooks 172 defined inslider legs 170 are configured and dimensioned to engage posts 164 oflatch member 156, as shown in FIGS. 11 and 12. Slider 158 is distallybiased by slider spring 174 which is maintained in axial alignment byslider post 166 of slider 158. The proximal end of slider spring 174bears against the inner surface of housing cover 108 and is maintainedin position between proximal post 178 and cylindrical base 180 formed inbase 106, (see FIGS. 9 and 10). The distal biasing of slider 158 causesarming button 168 to project through opening 180 formed in housing base106. The lower end or transverse leg 182 of slider 158 resides withmounting posts 172 a-c of housing base 106 with post base 184 of slider158 residing within mounting posts 172 b, 172 c. (See FIG. 9). Mountingof obturator assembly 100 relative to cannula assembly 112 causes slider158 to translate or rotate generally vertically in a generally proximaldirection as will be described further hereinbelow.

With reference to FIGS. 4-6, in conjunction with FIG. 3, the componentsof obturator shaft 104 will be discussed. Obturator shaft 104 includesobturator rod 186, blade mount 188 and blade 190. Obturator rod 186defines proximal end 192 having a general semi-circular cross-sectionand being received within correspondingly dimensioned opening 194 ofspring mount 154 of housing cover 108 (see FIG. 10). The proximal end192 further defines latch 196 which is received within side opening 198of spring mount 154 in snap relation therewith to secure the twocomponents (see FIG. 6).

With reference now to FIG. 13, in conjunction with FIG. 3, the distalend of obturator rod 186 defines collar 200. Blade mount 188 includesmounting recess 202 which is dimensioned to receive collar 200 ofobturator rod 186. Mounting recess 202 is dimensioned to permit rotationof collar 200 and obturator rod 186 relative to blade mount 188. Blademount 188 further includes knife slot 204 which accommodates knife blade190. Knife blade 190 may be secured within knife slot 204 byconventional means including adhesives, cements, etc. Knife blade 196 ispreferably a flat or thin blade and fabricated from stainless steel by asuitable process, e.g., by stamping or metal injection molding andincludes opposed cutting edges 206 which extend to penetrating tip 208.

With reference now to FIGS. 14-15, a method of use and operation oftrocar assembly 10 will be discussed. Obturator assembly 100 is insertedwithin cannula assembly 1000 and advanced to where obturator housing 102is approximated with seal housing 2002 of the seal assembly 2000. Sealassembly 2000 may comprise a separate part or may be a component ofcannula assembly 1000. Seal housing 2002 and housing base 106 ofobturator housing 102 may be appropriately dimensioned to form afriction fit or may be coupled to each other by conventional meansincluding bayonet coupling, tongue-groove, etc. Approximating theobturator housing 102 and the seal housing 202 releases the blade guard120 from a locked condition, actuating the trocar assembly. With theobturator housing 102 and seal housing 2002 approximated, arming button168 of slider 158 engages surface 2004 of seal housing 2002 and isforced upwardly (depicted by directional arrow “u”) from the positiondepicted in FIG. 5 to the position depicted in FIGS. 14-15. During thismovement, slider 158 pivots or angulates whereby legs 170 of slider 158push latch member 156 in a radial outward direction (depicted bydirectional arrow “z”) such that web portion 162 of latch member 156 isout of axial alignment with ledge 144 of indicator collar 132. In thisposition, indicator collar 132 and protective shield 114 are free toaxially move.

Referring now to FIGS. 16-17, the surgeon begins to insert trocarassembly 10 through the body wall of the patient. Blade guard 120contacts the tissue and is driven upwardly to cause protective shield114 and indicator collar 132 to move proximally (depicted by directionalarrow “v”) against the bias of coil spring 148. Such movement exposesobturator blade 190 to incise the tissue. This armed condition ofobturator assembly 100 is visually verified by the proximal location ofindicator flag 140 of indicator collar 132. In addition, proximalmovement of indicator collar 132 causes posts 146 of the indicatorcollar 132 to ride along outer surfaces 170 a of legs 170 of slider 158to thereby move the slider 158 at least radially inwardly and upwardly(as shown by the directional arrows “r”) in a general aligned positionrelative to the obturator axis “x”. FIG. 17 illustrates this actuatedposition of latch member 156. With obturator blade 190 exposed, thesurgeon may apply a distally-directed force to obturator assembly 100 tocause penetration through the tissue. The surgeon may rotate obturatorhousing 102 during manipulation and advancement of obturator assembly100 into the tissue without concern of obturator blade 190 rotating. Inparticular, the rotatable coupling of obturator rod 186 with knife mount188 allows the knife blade 190 to remain stationary within the tissueeven in the surgeon rotates obturator housing 102. In addition, uponrotation of obturator housing 102, protective shield 114 includingshield member 116, shield extension 118 and blade guard 120 also remainstationary due to the rotatable coupling of shield member 116 withindicator collar 132. This is desirable in that any rotational movementof knife blade 190 may cause unnecessary damage to the tissue of thepatient. FIGS. 18-19 illustrate rotation of obturator housing 102 whileblade guard 120 and knife blade 190 remain stationary during advancementof trocar assembly 10 within tissue “t”. It is noted that indicator flag140 in its proximal position provides visual confirmation of the armedcondition of knife blade 190.

Once knife blade 190 and blade guard 120 pass through the body wall ofthe patient protective shield 114 moves distally to cover blade 190 andledge 144 of indicator collar 132 moves into engagement with web portion162 of latch member 156. In particular, indicator collar 132 andprotective shield 116 are driven distally under the influence of coilspring 148. Concurrently with this movement, slider 158, which isaligned relative to axis “x”, is driven distally under the influence ofcoil spring 174. In the respective positions of indicator collar 132 andslider 158 depicted in FIGS. 4 and 5, collar ledge 144 of indicatorcollar 132 securely engages web 162 of latch member 156 to secureprotective shield 114 in its extended position. The obturator assembly100 is removed from cannula assembly 1000 and surgery is performed withinstruments inserted through cannula assembly 1000.

With reference to FIGS. 20-23, alternative embodiments of indicatorcollar and shield member are illustrated. This embodiment is adapted toalso permit relative rotation of these two components. Indicator collar300 includes internal bore 302 and recess 304 extending through sidewall 306 of the collar 300. Indicator collar 300 further definesinternal annular tab 308 extending inwardly within bore 302. Shieldmember 310 defines annular peripheral slot or neck 312 having a reducedcross-section relative to the cross-sections of adjacent shield sections314, 316. In the assembled condition of the components, peripheral slot312 receives annular tab 308 of indicator collar 300 with shield sectionor head 314 within bore 302 of the collar 300. Peripheral slot 312 andannular tab 308 are appropriately dimensioned to permit rotation of thecomponents. In other respects, indicator collar 300 and shield member310 operate in a similar manner to their counterpart components in theembodiment of FIGS. 1-19.

Except where noted otherwise, the materials utilized in the componentsof the presently disclosed trocar assembly generally include materialssuch as, for example, ABS, polycarbonate, stainless steel, titanium andany other suitable biocompatible metals and/or polymeric materials. Apreferred ABS material is CYCOLAC which is available from GeneralElectric. A preferred polycarbonate material is also available fromGeneral Electric under the trademark LEXAN. An alternative polycarbonatematerial which may be utilized is CALIBRE polycarbonate available fromDow Chemical Company. The polycarbonate materials may be partially glassfilled for added strength.

Although the illustrative embodiments of the present disclosure havebeen described herein with reference to the accompanying drawings, it isto be understood that the disclosure is not limited to those preciseembodiments, and that various other changes and modifications may beeffected therein by one skilled in the art without departing from thescope or spirit of the disclosure.

1. A surgical penetrating system, which comprises: a housing; a shaftconnected to the housing; a blade coupled to the shaft such that theblade is rotatable relative to the shaft about a longitudinal axisthereof, the blade being generally flat; and a protective membercoaxially mounted about the blade and being adapted for longitudinalmovement between a first position substantially enclosing the blade anda second position to at least partially expose the blade.
 2. Thesurgical penetrating system of claim 1 including a latch memberpositioned in the housing to prevent longitudinal movement of theprotective member.
 3. The surgical penetrating system of claim 2 whereinthe latch member has an initial position securing the protective memberin the first position.
 4. The surgical penetrating system of claim 3wherein the latch member is movable to an actuated position operativelyreleasing the protective member to permit the protective member to moveto the second position thereof.
 5. The surgical penetrating system ofclaim 1 including a blade mount connected to the shaft, the blade mountand the shaft adapted for relative rotational movement about thelongitudinal axis, the blade mount housing the blade.
 6. The surgicalpenetrating system of claim 1 wherein the shaft is secured to thehousing whereby rotational movement of the housing causes correspondingrotational movement of the shaft.
 7. The surgical penetrating system ofclaim 1 wherein the protective member is normally biased toward thefirst position.
 8. The surgical penetrating system of claim 4 includinga release member mounted to the housing and operatively coupled with thelatch member, the release member adapted to move the latch member to theactuated position.
 9. The surgical penetrating system of claim 8 whereinthe release member includes a release button configured to displace therelease member and cause movement of the latch member to the actuatedposition.
 10. The surgical penetrating system of claim 4 including anindicator collar disposed within the housing and mounted to theprotective member, the indicator collar being adapted for longitudinalmovement with the protective member upon movement of the latch member tothe actuated position.
 11. The surgical penetrating system of claim 10wherein the indicator collar and the protective member are adapted forrelative rotational movement.
 12. The surgical penetrating system ofclaim 10 wherein the indicator collar includes an indicator memberadapted for providing visual confirmation to the user of the positioningof the protective member.
 13. The surgical penetrating system of claim 1wherein the shaft is at least partially positionable within a cannula.14. The surgical penetrating system of claim 13 wherein the cannulaincludes a cannula housing and a cannula sleeve extending from thecannula housing.
 15. The surgical penetrating system of claim 1 whereinthe protective member is positioned within the housing and rotatablerelative to the housing.
 16. The surgical penetrating system of claim 1wherein the housing is adapted for rotational movement relative to theblade.
 17. A surgical penetrating system, which comprises: a housing; ashaft connected to the housing; a blade coupled to the shaft such thatthe blade is rotatable with respect to the shaft, the blade beinggenerally flat; a protective member coaxially mounted about the bladeand being adapted for longitudinal movement between a first positionsubstantially enclosing the blade and a second position to at leastpartially expose the blade, the housing adapted for rotational movementrelative to the protective member and to the blade.
 18. The surgicalpenetrating system of claim 17 including a latch member positioned inthe housing to prevent longitudinal movement of the protective member.19. The surgical penetrating system of claim 17 wherein the shaft is atleast partially positionable within a cannula.
 20. The surgicalpenetrating system of claim 19 wherein the cannula includes a cannulahousing and a cannula sleeve extending from the cannula housing.